I recently had the tile on my shower floor regrouted. Shortly after this was done, I found a hairline crack spanning three tiles. The company claims that regrouting could not have caused this? Could it? What can I do other than retiling my whole floor?
Carol

I agree re-grouting would not have cause tiles to crack.

If you can find matching tiles you can replace cracked ones. Remove grout and smack with hammer to break up. Remove pieces, scrap floor and set new tiles. If you cannot find matching tiles you may be able to use another color or design that serve as accent pieces. Should differ in color from rest to look like it was done intentionally. Have to be same size.

Can I seal the cracks someway.
Will hairline cracks in shower tile floor cause water damage?

No real way to seal cracks that I know of. Cracks are too small to get any kind of sealer in. Should not have any water damage. There is a water proof pan underneath the concrete. Moisture in concrete is forced into drain.